Tear flow analysis through the upper and lower systems.

Using quantitative lacrimal scintillography, tear flow in the normal state was analyzed in 11 asymptomatic volunteers. The results were compared to states with the superior punctum occluded, and to those with the inferior punctum occluded. No significant difference in tear flow between the superior and inferior canaliculi was appreciated (P less than 0.05). Furthermore, no significant difference was noted in overall basal tear flow when one canaliculus was blocked compared to the patent system (P less than 0.05). This implies increased tear flow through the patent canaliculus when the opposite one is blocked. The clinical implications of these results are important in canaliculus repair after injury.